Change the way Perl modules are installed, update the default Perl to 5.18.
Before, we had:
site_perl : lib/perl5/site_perl/5.18
site_perl/perl_arch : lib/perl5/site_perl/5.18/mach
perl_man3 : lib/perl5/5.18/man/man3
Now we have:
site_perl : lib/perl5/site_perl
site_arch : lib/perl5/site_perl/mach/5.18
perl_man3 : lib/perl5/site_perl/man/man3
Modules without any .so will be installed at the same place regardless of the

Update search.cpan.org WWW: entries to have a trailing slash.
Change some URLs from author dirs to dist dirs.
The example in the porter's handbook didn't have the trailing slash;
mea culpa for not having caught that when it went in.